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Thread: math question "n(n-1)/2"

  1. October 31st, 2002, 03:57 AM #1
    cyclops07
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    Question math question "n(n-1)/2"

    In symmetric cryptography, the key must be "n(n-1)/2"...
    does anybody knows why the formula must be "n(n-1)/2"...
    anyone can explain bout the formula?
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  2. October 31st, 2002, 03:57 AM #2
    cyclops07
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    Question math question "n(n-1)/2"

    In symmetric cryptography, the key must be "n(n-1)/2"...
    does anybody knows why the formula must be "n(n-1)/2"...
    anyone can explain bout the formula?
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  3. October 31st, 2002, 04:22 AM #3
    Showtime8000
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    Ummm.....maybe

    Ya know, I remember that formula from geometry class...... A triangular pattern?

    Sorry Im still young and not too "in-tune" with math yet.
    It\'s 106 miles to Chicago, we\'ve got a full tank of gas, half a pack of cigarettes, it\'s dark and we\'re wearing sunglasses.

    Hit it!
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  4. October 31st, 2002, 04:22 AM #4
    Showtime8000
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    Ummm.....maybe

    Ya know, I remember that formula from geometry class...... A triangular pattern?

    Sorry Im still young and not too "in-tune" with math yet.
    It\'s 106 miles to Chicago, we\'ve got a full tank of gas, half a pack of cigarettes, it\'s dark and we\'re wearing sunglasses.

    Hit it!
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  5. October 31st, 2002, 05:03 AM #5
    Jabberwocky
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    well i don't know what it has to do with crypto, but that formula is used to find the sum of all numbers prior to n.

    ex: if you want the sum of all numbers leading up to 10, then
    10(9) / 2 = 45

    is the same as
    1+2+3+4+5+6+7+8+9 = 45

    i hope that sheds some light on something.
    U suk at teh intuhnet1!!1!1one
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  6. October 31st, 2002, 05:03 AM #6
    Jabberwocky
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    well i don't know what it has to do with crypto, but that formula is used to find the sum of all numbers prior to n.

    ex: if you want the sum of all numbers leading up to 10, then
    10(9) / 2 = 45

    is the same as
    1+2+3+4+5+6+7+8+9 = 45

    i hope that sheds some light on something.
    U suk at teh intuhnet1!!1!1one
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  7. October 31st, 2002, 07:01 AM #7
    (V)/\><
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    http://www.maths.mq.edu.au/~steffen/...ort/node7.html

    i just found this on google, it gives good insight into anti/symmetric cryptography.

    from what i know, coupled with this, i still can't think why the key must be n(n-1)/2.

    should it be a function? like p = n(n-1)/2 . could it be used to transform some ascii string into some larger bit number?

    in short, i don't know.
    Hmm...theres something a little peculiar here. Oh i see what it is! the sentence is talking about itself! do you see that? what do you mean? sentences can\'t talk! No, but they REFER to things, and this one refers directly-unambigeously-unmistakably-to the very sentence which it is!
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  8. October 31st, 2002, 07:01 AM #8
    (V)/\><
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    http://www.maths.mq.edu.au/~steffen/...ort/node7.html

    i just found this on google, it gives good insight into anti/symmetric cryptography.

    from what i know, coupled with this, i still can't think why the key must be n(n-1)/2.

    should it be a function? like p = n(n-1)/2 . could it be used to transform some ascii string into some larger bit number?

    in short, i don't know.
    Hmm...theres something a little peculiar here. Oh i see what it is! the sentence is talking about itself! do you see that? what do you mean? sentences can\'t talk! No, but they REFER to things, and this one refers directly-unambigeously-unmistakably-to the very sentence which it is!
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  9. October 31st, 2002, 10:35 AM #9
    nabylbt
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    I might try to explain this but first check this out:
    http://www.iam.unibe.ch/~mseeberg/theory.html
    http://www.informatik.uni-bremen.de/~hs/Lehre/L11.pdf

    Basically, the stated formula on top is used to estimate the entropy of the encryption key, ie how easily the key used can be reversed .... somehow it's an approximation
    hope that help
    assembly.... digital dna ?
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  10. October 31st, 2002, 10:35 AM #10
    nabylbt
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    I might try to explain this but first check this out:
    http://www.iam.unibe.ch/~mseeberg/theory.html
    http://www.informatik.uni-bremen.de/~hs/Lehre/L11.pdf

    Basically, the stated formula on top is used to estimate the entropy of the encryption key, ie how easily the key used can be reversed .... somehow it's an approximation
    hope that help
    assembly.... digital dna ?
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